diff --git a/source/blender/blenkernel/intern/blendfile_link_append.cc b/source/blender/blenkernel/intern/blendfile_link_append.cc
index 33025afb757..f9b9b09face 100644
--- a/source/blender/blenkernel/intern/blendfile_link_append.cc
+++ b/source/blender/blenkernel/intern/blendfile_link_append.cc
@@ -1495,6 +1495,7 @@ void BKE_blendfile_link(BlendfileLinkAppendContext *lapp_context, ReportList *re
 
   if ((lapp_context->params->flag & FILE_LINK) != 0) {
     blendfile_link_append_proxies_convert(lapp_context->params->bmain, reports);
+    BKE_main_mesh_legacy_convert_auto_smooth(*lapp_context->params->bmain);
   }
 
   BKE_main_namemap_clear(lapp_context->params->bmain);
diff --git a/source/blender/blenkernel/intern/mesh_legacy_convert.cc b/source/blender/blenkernel/intern/mesh_legacy_convert.cc
index 596745e6359..e66fee30fc3 100644
--- a/source/blender/blenkernel/intern/mesh_legacy_convert.cc
+++ b/source/blender/blenkernel/intern/mesh_legacy_convert.cc
@@ -35,6 +35,7 @@
 #include "BKE_customdata.hh"
 #include "BKE_global.h"
 #include "BKE_idprop.hh"
+#include "BKE_lib_id.hh"
 #include "BKE_main.hh"
 #include "BKE_mesh.hh"
 #include "BKE_mesh_legacy_convert.hh"
@@ -2235,17 +2236,105 @@ static bNodeTree *add_auto_smooth_node_tree(Main &bmain)
     nodeSetSelected(node, false);
   }
 
+  BKE_ntree_update_main_tree(&bmain, group, nullptr);
+
   return group;
 }
 
-static ModifierData *create_auto_smooth_modifier(Object &object,
-                                                 const FunctionRef<bNodeTree *()> get_node_group,
-                                                 const float angle)
+static VectorSet<const bNodeSocket *> build_socket_indices(const Span<const bNode *> nodes)
+{
+  VectorSet<const bNodeSocket *> result;
+  for (const bNode *node : nodes) {
+    LISTBASE_FOREACH (const bNodeSocket *, socket, &node->inputs) {
+      result.add_new(socket);
+    }
+    LISTBASE_FOREACH (const bNodeSocket *, socket, &node->outputs) {
+      result.add_new(socket);
+    }
+  }
+  return result;
+}
+
+/* Checks if the node group is the same as the one generated by #create_auto_smooth_modifier. */
+static bool is_auto_smooth_node_tree(const bNodeTree &group)
+{
+  if (group.type != NTREE_GEOMETRY) {
+    return false;
+  }
+  const Span<const bNode *> nodes = group.all_nodes();
+  if (nodes.size() != 10) {
+    return false;
+  }
+  if (!group.geometry_node_asset_traits) {
+    return false;
+  }
+  if (group.geometry_node_asset_traits->flag != GEO_NODE_ASSET_MODIFIER) {
+    return false;
+  }
+  const std::array<StringRef, 10> idnames({"NodeGroupOutput",
+                                           "NodeGroupInput",
+                                           "NodeGroupInput",
+                                           "GeometryNodeSetShadeSmooth",
+                                           "GeometryNodeSetShadeSmooth",
+                                           "GeometryNodeInputMeshEdgeAngle",
+                                           "GeometryNodeInputEdgeSmooth",
+                                           "GeometryNodeInputShadeSmooth",
+                                           "FunctionNodeBooleanMath",
+                                           "FunctionNodeCompare"});
+  for (const int i : nodes.index_range()) {
+    if (nodes[i]->idname != idnames[i]) {
+      return false;
+    }
+  }
+  if (nodes[3]->custom1 != int16_t(bke::AttrDomain::Edge)) {
+    return false;
+  }
+  if (static_cast<bNodeSocket *>(nodes[4]->inputs.last)
+          ->default_value_typed<bNodeSocketValueBoolean>()
+          ->value != true)
+  {
+    return false;
+  }
+  if (nodes[4]->custom1 != int16_t(bke::AttrDomain::Face)) {
+    return false;
+  }
+  if (nodes[8]->custom1 != NODE_BOOLEAN_MATH_AND) {
+    return false;
+  }
+  if (static_cast<NodeFunctionCompare *>(nodes[9]->storage)->operation != NODE_COMPARE_LESS_EQUAL)
+  {
+    return false;
+  }
+  if (BLI_listbase_count(&group.links) != 9) {
+    return false;
+  }
+
+  const std::array<int, 9> link_from_socket_indices({16, 15, 3, 36, 19, 5, 18, 11, 22});
+  const std::array<int, 9> link_to_socket_indices({23, 0, 24, 20, 21, 8, 9, 12, 10});
+  const VectorSet<const bNodeSocket *> socket_indices = build_socket_indices(nodes);
+  int i;
+  LISTBASE_FOREACH_INDEX (const bNodeLink *, link, &group.links, i) {
+    if (socket_indices.index_of(link->fromsock) != link_from_socket_indices[i]) {
+      return false;
+    }
+    if (socket_indices.index_of(link->tosock) != link_to_socket_indices[i]) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+static ModifierData *create_auto_smooth_modifier(
+    Object &object,
+    const FunctionRef<bNodeTree *(Library *library)> get_node_group,
+    const float angle)
 {
   auto *md = reinterpret_cast<NodesModifierData *>(BKE_modifier_new(eModifierType_Nodes));
   STRNCPY(md->modifier.name, DATA_("Auto Smooth"));
   BKE_modifier_unique_name(&object.modifiers, &md->modifier);
-  md->node_group = get_node_group();
+  md->node_group = get_node_group(object.id.lib);
+  id_us_plus(&md->node_group->id);
 
   md->settings.properties = idprop::create_group("Nodes Modifier Settings").release();
   IDProperty *angle_prop = idprop::create("Socket_1", angle).release();
@@ -2265,14 +2354,43 @@ static ModifierData *create_auto_smooth_modifier(Object &object,
 
 void BKE_main_mesh_legacy_convert_auto_smooth(Main &bmain)
 {
+  using namespace blender;
   using namespace blender::bke;
 
-  /* Add the node group lazily and share it among all objects in the main database. */
-  bNodeTree *node_group = nullptr;
-  const auto add_node_group = [&]() {
-    node_group = add_auto_smooth_node_tree(bmain);
-    BKE_ntree_update_main_tree(&bmain, node_group, nullptr);
-    return node_group;
+  /* Add the node group lazily and share it among all objects in the same library. */
+  Map<Library *, bNodeTree *> group_by_library;
+  const auto add_node_group = [&](Library *library) {
+    if (bNodeTree **group = group_by_library.lookup_ptr(library)) {
+      /* Node tree has already been found/created for this versioning call. */
+      return *group;
+    }
+    /* Try to find an existing group added by previous versioning to avoid adding duplicates. */
+    LISTBASE_FOREACH (bNodeTree *, existing_group, &bmain.nodetrees) {
+      if (existing_group->id.lib != library) {
+        continue;
+      }
+      if (is_auto_smooth_node_tree(*existing_group)) {
+        group_by_library.add_new(library, existing_group);
+        return existing_group;
+      }
+    }
+    bNodeTree *new_group = add_auto_smooth_node_tree(bmain);
+    /* Remove the default user. The count is tracked manually when assigning to modifiers. */
+    id_us_min(&new_group->id);
+
+    if (new_group->id.lib != library) {
+      /* Move the node group to the requested library so that library data-blocks don't point to
+       * local data-blocks. This requires making sure the name is unique in that library and
+       * changing the name maps to be consistent with the new state. */
+      new_group->id.lib = library;
+      BKE_id_new_name_validate(&bmain, &bmain.nodetrees, &new_group->id, nullptr, false);
+      if (library) {
+        new_group->id.tag |= LIB_TAG_INDIRECT;
+      }
+    }
+
+    group_by_library.add_new(library, new_group);
+    return new_group;
   };
 
   LISTBASE_FOREACH (Object *, object, &bmain.objects) {
@@ -2284,7 +2402,6 @@ void BKE_main_mesh_legacy_convert_auto_smooth(Main &bmain)
     if (!(mesh->flag & ME_AUTOSMOOTH_LEGACY)) {
       continue;
     }
-    mesh->flag &= ~ME_AUTOSMOOTH_LEGACY;
 
     /* Auto-smooth disabled sharp edge tagging when the evaluated mesh had custom normals.
      * When the original mesh has custom normals, that's a good sign the evaluated mesh will
@@ -2333,6 +2450,10 @@ void BKE_main_mesh_legacy_convert_auto_smooth(Main &bmain)
       BLI_addtail(&object->modifiers, new_md);
     }
   }
+
+  LISTBASE_FOREACH (Mesh *, mesh, &bmain.meshes) {
+    mesh->flag &= ~ME_AUTOSMOOTH_LEGACY;
+  }
 }
 
 namespace blender::bke {
diff --git a/source/blender/blenloader/intern/versioning_common.cc b/source/blender/blenloader/intern/versioning_common.cc
index 1e428e3c975..c86df3ba23b 100644
--- a/source/blender/blenloader/intern/versioning_common.cc
+++ b/source/blender/blenloader/intern/versioning_common.cc
@@ -532,7 +532,10 @@ void do_versions_after_setup(Main *new_bmain, BlendFileReadReport *reports)
     BKE_lib_override_library_main_hierarchy_root_ensure(new_bmain);
   }
 
-  if (!blendfile_or_libraries_versions_atleast(new_bmain, 401, 2)) {
+  if (!blendfile_or_libraries_versions_atleast(new_bmain, 402, 22)) {
+    /* Initial auto smooth versioning started at (401, 2), but a bug caused the legacy flag to not
+     * be cleared, so it is re-run in a later version when the bug is fixed and the versioning has
+     * been made idempotent. */
     BKE_main_mesh_legacy_convert_auto_smooth(*new_bmain);
   }
 }